Laminin, an 850 Kda basement membrane glycoprotein, has been reported to stimulate directed cell migration (chemotaxis) of rabbit peritoneal exudate neutrophils (PMN). Human PMN express receptors for laminin, however, the chemoattractant activity of laminin for human PMN remains undefined. Laminin, isolated from Engelbreth-Holm-Swarm tumor, and ten synthetic peptides corresponding to various regions of the laminin A and B1 chains were compared for their abilities to stimulate human PMN chemotaxis and activated random migration (chemokinesis) through polycarbonate membrane filters in a 48-well microchemotaxis assay. Peptides F-9, F-11, F-12, and F-13 were derived from the laminin B1 chain cross-region (J. Cell Biol. 1988, 107:1253), while six peptides were derived from the laminin A chain (J. Invest. Derm., 1991, 97:141): peptide TG-1 from the amino terminus top globule; peptides GD-1, GD-3, GD-6, and GD-7 from the carboxy terminus globular domain; and peptide AG-1 from above the carboxy terminus globular domain. Laminin and the peptides were evaluated over a concentration range of 1-200 ug/ml in the motility assays. Only four of the peptides, F-12, TG-1, GD-6 and GD-1, stimulated PMN chemokinetic migration. Laminin and the other peptides failed to stimulate human PMN migration. In contrast, laminin stimulated rabbit peripheral blood PMN chemokinesis. These results demonstrate a species difference in human and rabbit PMN motility responses to laminin. Three peptides from the laminin A chain, TG-1, GD-6, and GD-1, and one peptide from the B1 chain, F-12, stimulate human PMN chemokinetic migration. These results suggest that specific laminin fragments which may be generated during basement membrane degradation can stimulate human neutrophil migration. The results of this study were presented at the 1991 American Society for Cell Biology Meeting and are submitted for publication as a manuscript.